UV-B induces DNA damage and DNA synthesis delay in the marine diatom Cyclotella sp

TY - JOUR

T1 - UV-B induces DNA damage and DNA synthesis delay in the marine diatom Cyclotella sp

AU - Buma, A.G.J.

AU - Van Hannen, E.J.

AU - Veldhuis, M.

AU - Gieskes, W.W.C.

N1 - Reporting year: 1996 Metis note: 2959; CL; AFW; file:///L:/Endnotedatabases/NIOOPUB/pdfs/Pdfs1996/Buma_ea_2959.pdf

PY - 1996

Y1 - 1996

N2 - The effect of UV-B on the occurrence of DNA damage and consequences for the cell cycle were studied in the marine diatom Cyclotella sp. DNA damage was quantified by immunofluorescent detection of thymine dimers in nuclear DNA of single cells using flow cytometry. A total UV-B dose (biologically effective dose BE(DNA300nm)) of 1.05 kJ m(-2) caused detectable damage in about 20% of the exposed population. In the period after the UV-B treatment, when the culture was exposed to PAR (450 mu mol m(-2)s(-1)) only, thymine dimers were removed; after 8 hours none of these photoproducts remained. Cellular DNA content measurements and quantification of the fraction of recently divided cells revealed that the DNA synthesis rate as well as the rate of cell division were reduced during and shortly after UV-B exposure. Apparently, UV-B irradiation extends the cell cycle of Cyclotella sp. in the S (DNA synthesis) phase until the dimers are removed. [KEYWORDS: cell cycle; DNA damage; flow-cytometry; marine diatom; thymine dimers; UV-B Ultraviolet-radiation; antarctica; dosimeter; dimers; ocean;cells]

AB - The effect of UV-B on the occurrence of DNA damage and consequences for the cell cycle were studied in the marine diatom Cyclotella sp. DNA damage was quantified by immunofluorescent detection of thymine dimers in nuclear DNA of single cells using flow cytometry. A total UV-B dose (biologically effective dose BE(DNA300nm)) of 1.05 kJ m(-2) caused detectable damage in about 20% of the exposed population. In the period after the UV-B treatment, when the culture was exposed to PAR (450 mu mol m(-2)s(-1)) only, thymine dimers were removed; after 8 hours none of these photoproducts remained. Cellular DNA content measurements and quantification of the fraction of recently divided cells revealed that the DNA synthesis rate as well as the rate of cell division were reduced during and shortly after UV-B exposure. Apparently, UV-B irradiation extends the cell cycle of Cyclotella sp. in the S (DNA synthesis) phase until the dimers are removed. [KEYWORDS: cell cycle; DNA damage; flow-cytometry; marine diatom; thymine dimers; UV-B Ultraviolet-radiation; antarctica; dosimeter; dimers; ocean;cells]

M3 - Article

SN - 0214-8358

VL - 60

SP - 101

EP - 106

JO - Scientia Marina

JF - Scientia Marina

ER -